This invention relates to mixing valves and, in particular, to mixing valves for use with faucets.
Mixing valves are frequently used with kitchen and bathroom faucets to obtain water at a desired temperature and rate of flow from separate sources of hot and cold water. Rather than providing one valve for control of the volume of hot water delivered to a discharge outlet in a given period of time and a second valve for control of the flow of cold water to the outlet, a single mixing valve combines the hot and cold water to control both the temperature and the flow rate of the water at the discharge outlet. This may be accomplished by providing a first adjustment for controlling the ratio of the volume of hot to the volume of cold water delivered to the outlet per unit time, and a second adjustment for controlling the total volume of water released from the outlet during a given amount of time.
In the past, mixing valves have employed relatively complicated valve operating mechanism requiring the assembly of many parts. Although some prior art devices have separate handles for controlling volume of flow and temperature, others employ a single handle which controls both water temperature and volume. However, with a single handle device, the temperature of the water is often changed accidentally when adjusting the flow rate.
Summarizing, prior art mixing valve operating mechanisms often utilize a large number of assembled parts, and are relatively difficult to disassemble and repair. Further, with some of the devices commonly in use, it is easy to accidentally change the temperature setting when the volume of water is changed and, therefore, with each new use of the valve, the temperature must be readjusted. Thus, there is a need for a mixing valve of simple construction in which the temperature of the water does not change as the rate of flow is varied.